Grifola frondosa (Maitake mushroom) is an important cultivated mushroom due to its medicinal and nutrient values. In this study, we isolated and characterized a novel partitivirus (named Grifola frondosa partitivirus 1, GfPV1) infecting a standard G. frondosa strain Gf-N2. This virus has a two-segmented dsRNA genome (dsRNA1 and dsRNA2) with nucleotide lengths of 2.3 and 2.2 kbp, respectively. The coding strand of dsRNA1 and dsRNA2 segments carries single open reading frame encoding RNA-dependent RNA polymerase (RdRp) and a coat protein (CP), respectively. BLAST searches and phylogenetic analyses showed that GfPV1 is most closely related to a betapartitivirus, Lentinula edodes partitivirus 1 (RdRp <70% and CP <60% amino acid sequence identities), but the sequence divergence suggests that GfPV1 is classifiable as a new member of the genus Betapartitivirus, family Partitiviridae. The presence of GfPV1 does not affect colony morphology and fruiting body development of G. frondosa. This is the first report investigating the effects of a mycovirus infection on the colony morphology and fruiting body development of G. frondosa. Interestingly, GfPV1 accumulations markedly decreased along with the fruiting body maturation stages, suggesting the inhibition of virus multiplication during sexual phase of the G. frondosa life cycle.

The Entoloma clypeatum species complex, known as “Harushimeji” in Japan, associates with Rosaceae and Ulmaceae plant species. In this study, we successfully isolated cultures of this fungal group via basidiospore isolation from tentative four Harushimeji species using modified Norkrans's C (MNC) medium and MNC medium containing n-butyric acid. Colony formations were observed on 22 of 25 basidioma samples; however, most exhibited slow and unsteady growth. The isolated mycelia contained dikaryotic hyphae and were identified through molecular phylogenetic analyses of the internal transcribed spacer region of fungal ribosomal RNA. Six isolates showing steady growth were deposited in the fungal culture collection of the Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, Japan. This result indicates that basidiospore isolation is a useful method for obtaining Harushimeji strains.

We report the discovery of the deep-sea fungus, Alisea longicolla on a wood log artificially immersed at 495 m depths in deep sea, off the Nansei Islands, Japan. Three different species of wood logs, whale bones and coconuts were deployed at approximate depths of 250, 500, 1000, 2000, 3000 and 5000 m. Densely colonised A. longicolla was found on the Ubame oak (Quercus phillyraeoides) wood log from the 500 m deployment site, which was collected 1302 d (about 3 y and 7 mo) after the deployment. Alisea longicolla was originally described as a new genus of deep-sea ascomycete within the family Halosphaeriaceae, associated with sunken wood collected in 630–791 m water depths off the Vanuatu Islands. Our results provide further evidence to support that A. longicolla may be an endemic deep-sea fungus, and it grows slowly but is active and reproductive in deep-sea environments. The occurrence of obligate deep-sea fungi appears to be very rare in the environments and few data is available. Further investigation on A. longicolla will extend our understanding of the ecology, physiology and evolution of deep-sea fungi.

Myxotrichum albicans sp. nov. is a slowly-growing fungal species that was isolated from forest litters in northeast of China. The new species is morphologically characterized by its white colonies on CMA, PCA, PDA, and YMA, thallic conidiogenous cells, simple, catenate and hyaline conidia. Phylogenetic analysis based on internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequences also supported the placement of M. albicans as a new species in the genus Myxotrichum. To compare with related species, the optimal pH and temperature for growth were investigated. The differences among Myxotrichum (Oidiodendron) species producing hyaline conidia were discussed.

The causal fungus of a rust disease of Rosa hirtula, endemic to mountainous areas of Fuji-Hakone-Izu National Park, Japan, was thought to be a common species Phragmidium rosae-multiflorae. Continued field observations, morphological examination, and experimental inoculations proved that the fungus produced laterally three-angled aeciospores and urediniospores together with multi-cellular teliospores on the same R. hirtula trees. These morphological features were different from those of P. rosae-multiflorae. The fungus parasitized only R. hirtula. Experimental inoculations and field observations did not prove that R. banksiae, R. laevigata, and R. multiflora supported infection and sporulation of the fungus. Under the field observations, R. multiflora, the most common host of P. rosae-multiflorae, was not proven to harbor the R. hirtula fungus. Therefore, the fungus was concluded to be a species distinct from P. rosae-multiflorae; and a new name, P. satoanum, was proposed for it.

Lentinula edodes secretes laccase (Lcc: EC 1.10.3.2), an industrially useful enzyme. In this study, we introduced and expressed the L. edodes Lcc gene, lcc1, driven by L. edodes glyceraldehyde-3-phosphate dehydrogenase gene promoter into L.edodes. The resulting transformants showed 2-fold Lcc activity than that of the host strain, and expression of the recombinant lcc1 was confirmed by RT-PCR.

Erysiphe longissima is a species of Erysiphe sect. Microsphaera endemic to China. Its asexual morph is poorly known and DNA sequence data are unrecorded since its first description in 1977. In 2016 and 2017, two powdery mildew samples with asexual and sexual morphs were collected on Caragana rosea at Jilin Agricultural University, Jilin Province, China. The morphological observations suggested that the two samples belonged to E. longissima. To study the phylogenetic position of E. longissima, a phylogenetic tree was constructed based on the combined ITS and 28S rDNA sequence data. This fungus was close to E. palczewskii in phylogeny and clearly distinguished from other species of Erysiphe sect. Microsphaera. To our knowledge, this is the first detailed record of the asexual morph and molecular data of E. longissima.

Endrin is persistent organic pollutants that contaminate soil in many parts of the world. In this study, endrin was used as the substrate for a degradation experiment with the white rot fungi of the genus Phlebia. The results of tolerance test showed that the tolerance level of Phlebia acanthocystis and Phlebia brevispora to endrin was higher than that of other fungi, and the tolerance coefficient of both strains to 1.0 mg/L endrin exceeded 0.9 in solid PDA medium. P. acanthocystis and P. brevispora could degrade endrin efficiently in pure culture, especially P. acanthocystis had the highest degradability of more than 80% after 20 d incubation. Compared with low-nitrogen medium, PDB medium is more suitable for the biodegradability of two fungi. Several hydroxylated products such as 8-hydroxyendrin and two monohydroxyendrin were detected, indicating that endrin was initially branched to different monohydroxylated products in fungal degradation. Moreover, a carboxylic acid product was obtained from P. acanthocystis culture, suggesting that the carboxylation reaction occurred in bioconversion of endrin. The fungal cytochrome P450 enzymes play significant role in the in the initial hydroxylation process on endrin degradation. This is the first report that endrin is converted to hydroxylated and carboxylated metabolites by microorganisms.

Chemical and physical properties (including ultraviolet spectrum) of a brown pigment isolated from Grifola frondosa fruiting bodies were almost identical to those of fungal melanin. From the full genome sequence of G. frondosa, genes involved in the melanin biosynthesis pathway of this polypore mushroom were identified, including tyrosinases (tyr1 and tyr2). Transcriptional analyses showed dramatic changes only in the expression of tyr2 in the primordial stage. Immuno-electron microscopy using anti-tyrosinase antibodies showed that TYR2 localizes in the cell walls of primordia. Therefore, TYR2 may be closely associated with melanin biosynthesis in this polypore mushroom G. frondosa, and melanin might be produced in the cell wall.